(Originais Teachy 2023) - Question Medium of Physics

A motor operates according to the Carnot cycle between two thermal sources. The hot source is at a temperature of 500 K and the cold source at 300 K. Determine the efficiency of the motor, knowing that the efficiency of the Carnot cycle is calculated by the expression 1 - (Tcold/Thot), where Tcold and Thot are the temperatures of the cold and hot sources, respectively. Discuss briefly the importance of the maximum efficiency of the Carnot cycle in practical applications of thermal engines.

The prefix table is used to represent physical quantities more accurately. For example, we can use the prefix 'deci' to represent 0.1 times the unit. If we have 1 decimeter, that means 0.1 meters. Which of the prefixes below means 0.000001 times the unit?

João is helping his father fill the home pool, which is rectangular and has the following dimensions: 8 meters in length, 4 meters in width, and 1.5 meters in depth. They are using a hose with a constant flow rate of 20 liters per minute. Considering that the pool was completely empty and there was no water wastage in the process, answer: (a) What is the total volume of the pool in liters? (b) How long, in hours, will it take to completely fill the pool with the hose? (c) If the water in the pool had the mentioned constant flow rate, but drained through an opening of the same size as the hose, how long would it take for the pool to completely empty?